Leftover Cream Cheese Filling?

I have an entire bowl full of cream cheese icing/filling left over from a 10/11/08 cake. Do you think it is still good? Or should I discard it and make a whole new batch. I need it for another cake this upcoming weekend. I know cream cheese lasts awhile if refrigerated. I used cream cheese, butter, shortening, powder sugar, vanilla, & salt in the recipe.